Extension-bit



P. BASMAISON.

EXTENSION BIT.

APPLICATION FILED NOV- 9.1920.

Patented Dec. 27, 1921.

2 $HEEISSHE'T l- IN VEN TOR. .Fz'err Emma It BY S A TTORNEYS.

P. BASMAISON. EXTENSION BIT. APPLICATION men NOV-9,1920} Patented Dec. 27, 1921.

2 SHEETSSHEE INVENTOR. Pi -re flqrgmazlfvn BY v ATTORNEYS.

40 L. and a limit stop for said center, and means it similar numerals refer to similar parts UNITED STATES PATENT OFFICE.

PIER-BE BASMAISON, OF SAN FRANCISCO, GALIIORNIL EXTENSION-BIT.

\ .T all whom it may concern:

y 1 Be it known that I, PIERRE BASMAISON, a

citizen of the United States, and resident of San Francisco, county of San Francisco, State of California, have invented a new and useful Extension-Bit, of which the following is a specification.

This invention relates to improvements in extension bits, and has for one of its objects the provision of means for increasing the strength of the bit and so reinforce the cutters that the bit will not stick even if the brace is not held steady.

Another object is to provide ample clearance for the shavings to prevent them from rolling up and blocking the passage of the bit in the channel. 1

Another object is to provide a bit that ma be easily sharpened with a flat file.

nother object is to provide a clamp for holding the two parts of the bit rigidly tother, and one that is easily adjusted and fiatmay be held very close to the center of the 5001. l

..Another object is to make a clamp adapted to hold bits ofvarious thicknesses. 1Another ob'ect is to provide a clamp for adjusting an holding the radial rod very rigd'idly without leaving any marks on the Another object is to provide a yielding center for the .tool and means for making said center rigid so that it may be used to punch a center hole.

Another object is to provide a gage for indicating when the brace is not held true, and also provide other uses for the gage such as glass cutting.

Another object is the provision of a spring for holding the yielding center out,

i .for replacing the yielding center with a bit v hold the center point from digging mto the or pin, and means for clamping them securely in any adjustedposition.

Another object isto provide a plate to material to be cut, and a further object is to provide means for setting the cutting bit at different angles to the perpendicular brace for boring tapered holes and cutting tapered it Other objects will appear to those skilled the art, as the description proceeds.

. An embodiment of the invention is shown in the accompanying drawing in which Specification of Letters Patent.

Patented Dec. 27, 1921.

Application filed November 9, 1920. Serial No. 422,852.

throughout the which- Figure 1 is a side tension bit.

Fig. 2 is an end the left of Fig. 1. i

Fig. 3 1s a plan view with parts broken away for purpose of illustration. Fig. 4 IS a view of the clamp head, looking from the right of Fig. 1

Fig. 5 is a view of the showing the groove and Fig. 6 is a detail of the clamping means for holding the radial rod. Flg. 7 is a bottom view of the post showing a detail of the yielding center pin lock. .Fig. 8 1s a side elevation of the extension bit for cutting a t per hole or plug by means of the angle attachment.

Fig. 9 is an end view of the angle attachment.

several views, and in elevation of the exelevation looking from yielding center pin stop in same.

Fig. 10 shows how the extension bit can be set to cut tapers of different angles.

Fig. 11 is a view looking atthe rounded surface of the bit, with the cutting bit and limit gage together. i

Fig. 12'is an edge view looking from the right of Fig. 11.

Fig. 13 is a view looking at the back or flat surface of the bit.

Fig. 14 is a view of the bottom portion of The numeral (1) indicates a post rovided with a shank (2) adapted to fit the chuck of a brace or other tool. Slidably mounted in the post is the radial rod (3). on the endof which is fixed the clamp head (4) whichis adapted to hold the limit gage (5), and the cutting bit (6) firmly together and in the seat by means of the bolt (7), the thumb nut (8), and the head (9) which has a cut away bevel edge (10) which acts against the bevel edge of the limit stop (5) to force it back in the seat, and sidewise against the member (6) which has a bevel edge (11) fitting the bevel in the seat. The limit gage (5) has a longitudinal groove 12) in which the longitudinal tongue fits. The cutting bit (6) has a depth cutting edge (14:) and a side cutter (15). The groove (16) is of a size to give ample clearance for the shavings. The limit gage (5) has a side cutter (17), a bearing surface (17) and a cut away portion (18) which allows clearance for the shavings. The radial rod has a ii-shaped groove (19) and is held in the desired radial adjustment by a pin (20) in the post The end 01' the pin is v shaped to lit the groove, a taper hole (21) is provided through the pin transversely, a thumb screw (22) is so mounted a that its taper portion (23) will engage the makev a rabbet.

bottom of the taper holeand force the pin (20) down and clamp the radial rod rigidly. At the end of the taper (23) astraight portion is provided and fits into a hole of the same size to take some or" the strain off the screw threads of (22). The yielding center consists preferably of a round pin (24), with a point (25), and isadapted to slide into a hole in the post (1) as shown by the dotted lines at (26). A spring (27) which hooks over a pin (28), and engages notches (29) in the post tends to hold the yielding center pin out. A groove (30) is provided in the pm. A thumb screw with a point fits into the groove (30), and is adjusted so the pin (24) can slide freely, the action of the spring holding the stop'pin (31) against the screw point The screw (32) is held securely by the locknut (32'), Means for locking the yielding center pin so it can be used for a punch is provided by having a lever (34L) pivoted at (35) so the edge will swing into a transverseslot (36) in the pin (24). The lever being of spring material a slight projection (37 which hooks over the corner of the post in the locked position and slides on the bottom in the free position holds th lever in the two positions. A boring gage (3S) mounted in the head this gage is so de signed that it can be held ri idly by the thumb screw (39), or it can be held by friction of a spring (40), the tension of which is adjusted by the'screw (41). A glass cutter (42) is mounted in the end of the gage which can be used by reversing the gage. The turned up portion (43) can be used to A center plate (4A) has sharp points around the edge, and a centering piece (46) may be used when the hole made by the center point is undesirable. For'cutting taper holes or plugs with the extension bit, an attachment for setting the post at various angles is shown in Figs. 8

link (50) at (51). The ends 01'' the bar are provided with slots and (56) adapted to slide on the thumb screw (57) in the extension (el8), and on the screw (58) in the shank (ii), the thumb screws being capable of clamping the bar rigidly in any position. li hcn he thumb screws are loosened the link free to swing in the arc of a circle A, and tilt the extension 18) with the post a an angle to the vertical line B with the point (25) touching said line, and thus the cutting bit is set to cut a circular gnoove (59) tapering toward the center line; while if the link is made to swing in the opposite direction the cutting bit is set to cut a circular groove (60) tapering away from the center line as shown in Fig. 10. In operation the shank (2) is clamped in the chuck of a brace, the limit gage (5) and cutting bit (6) are placed together and clamped in the seat at the required height in the head l) by means of the screw (7), thumb nut (8) and clamping head (9), then the radial rod (3) is moved to set the cutting bit at the required radius of the circle to be cut, and is clamped in place by means of the thumb screw which forces the pin (20) into the groove (19) as described. Now in order to make a center hole, the yielding center is made rigid by throwing the lever (34) so its edge enters the slot (36), then the center pin can be used as a punch to make a suitable hole. The brace being perpendicular, the gage is adjusted to touch the surface oi? the material to be cut, the thumb screw (39) loosened, and the spring (40) set at the required tension; if the gage touches evenly all around as the brace is turned, it indicates that the brace is held in the proper position. For cutting glass the gage is reversed and held in position by the thumb screw (39), a center is provided by the plate using a strip of rubber or the like under the plate on the glass.

My claims are as follows, but various modifications may be made in the above described form within the scope of my inven tion.

I claim:

1. An extension bit comprising a rotatable post, a rap ial rod slidable through said post, clamping means for said rod, a center pin ai'lapted to telescope into said post longitudinally, a transverse slot in said pin, a pivoted lever on said post, one edge of: said lever being adapted to slide into said slot and hold said pin rigidly for the purpose described.

2. 111 an extension bit comprising a rotatable post with a shank adapted to receive the chuck of a brace or like tool, a spring extended center pin adapted to telescope into said post longitudinally, a limit stop for said center pin, a radial rod adapted to slide through said post transversely, means for clamping said rod and said post together, a

head on said rod, a seat for a cutting bit in said head, means for clamping said bit to said head, a gage rod adapted to slide through said head parallel with said bit, rigid means and spring means adapted to be selectively used for holding the gage in a desired position.

3. An extension bit, comprising a rotatable post, an adjustable transverse rod in said post, a tool holder on said rod, an extension to said post, an auxiliary shank, a connecting link, one end of which is pivoted on said shank and the other end pivoted on said extension, a side bar pivoted on said link, one end of said bar being slotted and connected to said shank by means of a screw through said slot, the other end being slotted and connected to said extension by means of a screw through said slot, the said screws being adapted to clamp said side bar firmly to said shank and said extension and thereby holding said link at any adjusted angle.

PLERRE BASMAISON. 

